The present invention relates to a system for indicating the necessity of four-wheel driving in a four-wheel drive vehicle for urging an operator to change the transmission from two-wheel drive operation to four-wheel drive operation.
In a four-wheel drive vehicle, a clutch device is provided to select either two-wheel drive operation or four-wheel drive operation. The clutch device is engaged by a manually operating select lever.
It is preferable to drive the vehicle in four-wheel drive on a slippery road such as roads with snow and ice. In a conventional four-wheel drive vehicle, the operator manipulates the select lever when he judges the necessity for the four-wheel drive. Generally, the judgement of the operator is not always suitable for the four-wheel drive and moreover, the operator must take care in judging the road condition.